UFO sighting and unknown explosions heard in the sky.wmv

Well this was my last sighting before i got home from my skywatch yesterday, i have no idea what those explosions where..

At first i thought it might had been firecrackers but i saw nothing near me, considering the fact that the sound came not far away from me i should had seen something that made a noise on that scale, of all of the time i have heard these loud explosions in the sky only once have it actually been "firecrackers" or fireworks.